<template>
  <view>
    <my-search @myClick="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <scroll-view scroll-y="true" class="left-scroll-view" :style="{height: wh +'px'}">
       <block v-for="(item,i) in cateList" :key="i">
         <view :class="['left-scroll-view-item',i === active ? 'active' : '']" @click="activeChange(i)">
           {{item.cat_name}}
         </view>
       </block>
      </scroll-view>
        <!-- 右侧滚动区域 -->
      <scroll-view scroll-y="true" class="right-scroll-view" :style="{height: wh + 'px'}" :scroll-top="scrollTop">
        <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
          <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
          <!-- 动态渲染三级分类的列表数据 -->
          <view class="cate-lv3-list">
            <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
              <image :src="item3.cat_icon.replace('dev', 'web')"></image>
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
 import badgeMix  from '@/mixins/tabbar-badge.js'
 
 export default {
    mixins:[badgeMix],
    data() {
      return {
         // 可用高度 = 屏幕高度 - navigationBar高度 - tabBar高度 - 自定义的search组件高度
        wh: 0,
        // 当前选中项的索引，默认让第一项被选中
        active:0,
        //分类数据
        cateList:[],
        // 二级分类列表
        cateLevel2: [],
        // 滚动条距离顶部的距离
        scrollTop: 0
      };
    },
    onLoad() {
       // 获取当前系统的信息
      const sysInfo = uni.getSystemInfoSync()
      // 为 wh 窗口可用高度动态赋值
      this.wh = sysInfo.windowHeight - 50
      
      //获取分类数据
      this.getCateList()
    },
    methods: {
      async getCateList() {
        const {data: res} = await uni.$http.get('/api/public/v1/categories')
        if(res.meta.status != 200) return uni.$showMsg()
        this.cateList = res.message
        this.cateLevel2 = res.message[0].children
      },
      activeChange(i) {
        this.active = i
        // 为二级分类列表重新赋值
        this.cateLevel2 = this.cateList[i].children
          // 让 scrollTop 的值在 0 与 1 之间切换
          this.scrollTop = this.scrollTop ? 0 : 1
      },
      gotoGoodsList(item3){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid=' + item3.cat_id
        })
      },
      gotoSearch(){
      
        uni.navigateTo({
          url:'/subpkg/search/search'
        })
      }
    }
  }
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px;

    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;

      // 激活项的样式
      &.active {
        background-color: #ffffff;
        position: relative;

        // 渲染激活项左侧的红色指示边线
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
  .cate-lv2-title {
    font-size: 12px;
    font-weight: bold;
    text-align: center;
    padding: 15px 0;
  }
  .cate-lv3-list {
    display: flex;
    flex-wrap: wrap;
  
    .cate-lv3-item {
      width: 33.33%;
      margin-bottom: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
  
      image {
        width: 60px;
        height: 60px;
      }
  
      text {
        font-size: 12px;
      }
    }
  }
}
</style>
